As is known, body control involves stabilizing or balancing the vehicle body, i.e., the body of the vehicle in the broadest sense, such that, for example, on inclined surfaces such as hillsides or on uneven terrain or when cornering, the effects on the body are reduced. This also includes, for example, rolling or pitching of the motor vehicle which must be controlled or reduced.
This function cannot be carried out by conventional vibration dampers. Both monotube dampers and twin-tube dampers are known, but are configured only for vibration damping.
Further, body control is to be distinguished from wheel control which comes into question when a vibration damper has an adjustable damping force. An adjustable damping force can be generated, for example, through an adjustable valve with which the flow resistance for the hydraulic medium in the vibration damper can be varied so that the damping force is also varied.
There are a number of different known systems by which body control can be carried out. For example, US 2009/0260935 A1 discloses a vibration damper which has a gerotor, i.e., a device which can be operated both as motor and as generator, which is coupled to a pump. This apparatus can be used to recuperate energy and to perform a body control and a wheel control. Accordingly, wheel control, body control and recuperation are achieved by the same apparatus. A vibration damper having the same operating principle is further disclosed in US 2013/0147205 A1 and US 2014/0265168 A1.
In contrast, DE 10 2009 022 328 A1 discloses a vibration damper in which the wheel control is carried out by a pressure regulating valve and the body control is carried out by a motor-pump unit. In this construction, the body control and the wheel control are implemented by independent units which can accordingly be optimized separately. A similar construction is shown in WO 2014/066469 A1. In this case, the adjustable damping forces are generated via adjustable valves, one for the rebound direction and one for the compression direction, and the body control is carried out via a motor-pump unit.
In order to utilize the vibration damper to compensate for road irregularities, it is known to use sensor data of cameras and, on this basis, to compensate the changing distance between vehicle body and road level such that road irregularities are not transmitted, or at least not transmitted in their entirety, to the vehicle body.
In the known chassis systems, there is the problem that they cannot simply be coupled to the energy power supply of the motor vehicle because the energy consumption and therefore the required energy supply is higher than that which can be made available by the vehicle power supply of the motor vehicle.
In view of the foregoing, it is an object of the present application to provide a method for operating a motor vehicle of the type mentioned above in which the chassis system can be operated via the vehicle power supply of the motor vehicle.